Hybrid energy storage systems for fast-developing renewable energy plants

To achieve zero carbon emissions, renewable energy sources are highly promising alternatives to fossil fuels. However, the intermittency of renewable energy sources hinders the balancing of power grid loads. Because energy storage systems (ESSs) play a critical role in boosting the efficiency of renewable energy sources and economizing energy generation, different ESSs and their applications in various environments must be comprehensively investigated. With sustained growth in the global demand for ESSs, reliance on a single technology may not comprehensively fulfill the anticipated requirements for the ESS cycling life, efficiency, cost, and energy/power densities. Hence, hybrid ESSs (HESSs), combining two/multiple ESSs, offer a promising solution to overcome the constraints of a single ESS and optimize energy management and utilization. Therefore, this review extensively and comprehensively describes ESSs, including their classifications, mechanisms, strengths, and weaknesses, and introduces several typical HESS energy management strategies and application domains.